Technical Field: Multi-fold doors for enclosed railcars.
The transportation of trucks, buses, large tractors and other large mobile freight by rail has created a demand for enclosed super size railcars, as most existing railcars do not have the appropriate internal dimensions to accommodate such large freight or are otherwise not able to enclose such freight. An enclosed railcar is preferred for transport because it minimizes exposure to the elements, vandalism and other general damage to the freight. Large enclosed railcars are presently used to transport automobiles and light trucks, several of which may be “stacked” vertically in the same multi-level railcar. The art discloses numerous ways of accomplishing the stacking of vehicles in a railcar by incorporating multiple decks, creating numerous levels so that the vehicles occupy space along the entire height of the car. The presence of intermediate decks in such large railcars, commonly called auto racks, obstructs the vertical height and horizontal width of the railcar interior so that individual, larger dimensioned vehicles, such as semi truck tractors, cannot fit or otherwise take advantage of these larger cars. Single level superstructure construction has been hindered by the need for alternate structural support, previously provided by intermediate decks or levels stabilizing the railcar to sufficiently sustain the bending load.
Construction of single level enclosed superstructure railcars has included manufacturing the entire railcar from scratch or alternatively converting an existing multi level super size railcar or other railcar by retrofitting it with a single level superstructure or shell, resulting in increased usable vertical height compared to that of the pre conversion railcar. Such conversion has often been limited, however, to applications of superstructures to existing multi level railcars or to railcar superstructures having widths commensurate with the width of the pre-conversion railcar.
Manufacturing single level enclosed railcars, like manufacturing most railcars, is very expensive and can be cost prohibitive. Construction or modification of a railcar must meet industry standards which dictate exterior dimensions and clearance, including the external width of the railcar relative to the length. There is a need in the industry to be able to economically manufacture an enclosed single level superstructure railcar having substantial unobstructed internal dimensions, both vertically and horizontally, while retaining structural stability.